Obesity Causes Insulin Resistance in Type 2 Diabetes

Researchers have published a new study in which they demonstrate one of the mechanisms by which obesity modulates glucose and lipid metabolism in mice, more specifically, diabetes. It does this through changes in the microRNA content of exosomes, vesicles that secrete all cells and are found in the blood. These changes in the pattern of microRNA lead to glucose intolerance and insulin resistance. The study, published in the journal PNAS, unmasks a pathological mechanism little explored so far and provides a new therapeutic target for the treatment of the metabolic syndrome.

The research, coordinated by Anna Novials, head of the Pathogenesis and Diabetes Prevention team at Idibaps and leader of the Ciberdem group, estimated that one-third of the world’s population will be affected by type 2 diabetes by 2050. This disease is associated with overweight and sedentary lifestyle, with obesity being one of the main causes of insulin resistance that triggers type 2 diabetes.

Changes in the profile of circulating microRNA in the blood are associated with several diseases, including metabolic disorders. These molecules can be used as biomarkers to improve disease diagnosis and monitor response to treatments.

Obesity Causes Insulin Resistance in Type 2 Diabetes

Researchers have studied the role of the microRNA contained within exosomes, vesicles that secrete tissues and that include proteins, lipids or RNA molecules, in the metabolic syndrome. They have done so with a model of a diabetic mouse that simulates this syndrome.

By means of a diet rich in fats, the animals become intolerant to glucose -as a prediabetic state-, have fatty liver and disorder in the metabolism of lipids.

The researchers analyzed the profile of microRNAs contained in the exosomes of these mice and obtained a panel by means of a bioinformatic analysis. The results show that obesity changes the profile of microRNAs in plasma exosomes in mice.

But most importantly, treating healthy mice with exosomes isolated from obese mice leads to glucose intolerance and insulin resistance. According to the researchers, “this study we have explained the role that exosomes and certain obesity-related microRNAs play in the emergence and development of insulin resistance and diabetes. Now, the future is to block these molecules so that the disease does not appear”.